Infusion device and method with drive device in infusion device and method with drive device in separable durable housing portion

ABSTRACT

A delivery device includes a durable housing portion and a separable disposable portion that selectively engage and disengage from each other. The disposable housing portion secures to the patient and may be disposed of after it has been in use for a prescribed period. Components that normally come into contact with a patient or with infusion media are supported by the disposable housing portion for disposal after the prescribed use, while the durable housing portion supports electronics for controlling delivery of infusion media from the reservoir and a drive device and drive linkage.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present invention relates to U.S. Application 60/678,290, filed May6, 2005, which is incorporated herein by reference in its entirety andfrom which the priority benefit under 35 USC 119(e) is claimed.

BACKGROUND OF THE INVENTION

Certain chronic diseases may be treated, according to modern medicaltechniques, by delivering a medication or other substance to a patient'sbody, either in a continuous manner or at particular times or timeintervals within an overall time period. For example, diabetes is achronic disease that is commonly treated by delivering defined amountsof insulin to the patient at appropriate times. Some common modes ofproviding an insulin therapy to a patient include delivery of insulinthrough manually operated syringes and insulin pens. However, othermodern systems employ programmable pumps to deliver controlled amountsof insulin to a patient.

Pump type delivery devices have been configured in external devices(that connect to a patient) or implantable devices (to be implantedinside of a patient's body). External pump type delivery devices includedevices designed for use in a stationary location (for example, in ahospital or clinic), and further devices configured for ambulatory orportable use (to be carried by a patient). Examples of some externalpump type delivery devices are described in Published PCT Application WO01/70307 (PCT/US01/09139) titled “Exchangeable Electronic Cards ForInfusion Devices” (which is owned by the assignee of the presentinvention), Published PCT Application WO 04/030716 (PCT/US2003/028769)titled “Components And Methods For Patient Infusion Device,” PublishedPCT Application WO 04/030717 (PCT/US2003/029019) titled “DispenserComponents And Methods For Infusion Device,” U.S. Patent ApplicationPublication No. 2005/0065760 titled “Method For Advision PatientsConcerning Doses Of Insulin,” and U.S. Pat. No. 6,589,229 titled“Wearable Self-Contained Drug Infusion Device,” each of which isincorporated herein by reference in its entirety.

External pump type delivery devices may be connected in fluid-flowcommunication to a patient-user, for example, through a suitable hollowtubing. The hollow tubing may be connected to a hollow needle that isdesigned to pierce the patient-user's skin and deliver infusion mediathere-through. Alternatively, the hollow tubing may be connecteddirectly to the patient as or through a cannula.

In contexts in which the hollow tubing is connected to the patientthrough a hollow needle that pierces the patient's skin, a manualinsertion of the needle into the patient can be somewhat traumatic tothe patient. Accordingly, insertion tools have been made to assist theinsertion of a needle into the patient, whereby a needle is forced by aspring to quickly move from a retracted position into an extendedposition. One example of such an insertion tool is described in U.S.Patent Application Publication No. 2002/0022855, titled “InsertionDevice For An Insertion Set And Method Of Using The Same” (assigned tothe assignee of the present invention), which is incorporated herein byreference in its entirety. As the needle is moved into the extendedposition, the needle is quickly forced through the patient's skin in asingle, relatively abrupt motion that can be less traumatic to a patientas compared to a slower, manual insertion of a needle.

As compared to syringes and insulin pens, pump type delivery devices canbe significantly more convenient to a patient, in that accurate doses ofinsulin may be calculated and delivered automatically to a patient atany time during the day or night. Furthermore, when used in conjunctionwith glucose sensors or monitors, insulin pumps may be automaticallycontrolled to provide appropriate doses of infusion medium atappropriate times of need, based on sensed or monitored levels of bloodglucose.

Pump type delivery devices have become an important aspect of modernmedical treatments of various types of medical conditions, such asdiabetes. As pump technologies improve and doctors and patients becomemore familiar with such devices, the popularity of external medicalinfusion pump treatment increases and is expected to increasesubstantially over the next decade.

However, many types of pump type delivery devices have been relativelyexpensive to obtain and to operate over a period of time. Some pump typedelivery devices require relatively complicated and time consumingprocedures for re-filling or replacing spent infusion media. Some pumptype delivery devices can only be used for a prescribed period of timeor require disposal or substantial rebuilding of key components after aprescribed number of uses.

Accordingly, a need exists for an infusion pump device and system thatmeets the increased demand for ambulatory infusion devices and thatcombines beneficial features of prior pump devices (includingcapabilities for continuous infusion, precision dosing, programmabledelivery schedules, controlled operation based on sensor or monitordata) with additional features that allow the pump device and system tobe operated economically and efficiently over a sufficient length oftime. A further need exists for such infusion pump devices and systemswhich include features for simplifying re-filling or replacement ofinfusion media.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a generalized diagram of a delivery system in relation to ahuman patient-user.

FIG. 2 is a perspective view of a delivery device and related componentsaccording to an embodiment of the invention.

FIGS. 3-12 each show a partial cross-sectional view of elements of adelivery device, including a motor, linkage and reservoir for a deliverydevice according to an embodiment of the present invention.

FIGS. 13 is a partially exploded view of a delivery device according toan embodiment of the invention.

FIGS. 14-16 show perspective views of various elements of the deliverydevice of FIG. 13.

FIGS. 17-24 and 28-30 each show a generalized perspective view of needleinsertion portions of delivery devices according to embodiments of thepresent invention.

FIG. 25 is a bottom view of a disposable portion of a delivery deviceaccording to an embodiment of the present invention.

FIG. 26 is a perspective view of a delivery device, showing internalstructure for distributing adhesive release agents according to anembodiment of the present invention.

FIG. 27 is a generalized diagram of an electronic system included in adelivery device according to an embodiment of the present invention.

FIGS. 31-36 are generalized perspective views of various needleconfigurations according to embodiments of the present invention.

DETAILED DESCRIPTION

The present invention relates, generally, to delivery devices, systemsand methods for delivering infusion media, such as a drug, to arecipient, such as a medical patient. In particular embodiments, adelivery device includes a disposable portion that secures to therecipient and that may be readily disposed of after it has been in usefor a period of time. Such embodiments may be configured to provide areliable, user-friendly mechanism to secure the delivery device to apatient for delivery of fluidic infusion media to the patient.Embodiments may be configured with feature that enhance the ease bywhich patients may secure the delivery device to the patient's skin andfurther features that enhance the ease by which patients may fill,re-fill or replace spent infusion media.

While embodiments of the present invention are described herein withreference to an insulin delivery example for treating diabetes, otherembodiments of the invention may be employed for delivering otherinfusion media to a patient for other purposes. For example, furtherembodiments of the invention may be employed for delivering other typesof drugs to treat diseases or medical conditions other than diabetes,including, but not limited to drugs for treating pain or certain typesof cancers, pulmonary disorders or HIV. Further embodiments may beemployed for delivering media other than drugs, including, but notlimited to, nutritional media including nutritional supplements, dyes orother tracing media, saline or other hydration media, or the like.

A generalized representation of an infusion media delivery system 10 isshown in FIG. 1, wherein the system includes a delivery device 12configured according to embodiments of the invention described herein.The system 10 may also include other components coupled forcommunication with the delivery device 12, including, but not limitedto, a sensor or monitor 14, a command control device (CCD) 16 and acomputer 18. Each of the CCD 16, the computer 18 and the delivery device12 may include receiver or transceiver electronics that allowcommunication with other components of the system. The delivery device12 may include electronics and software for analyzing sensor data andfor delivering infusion media according to sensed data and/orpre-programmed delivery routines. Some of the processing, deliveryroutine storage and control functions may be carried out by the CCD 16and/or the computer 18, to allow the delivery device 12 to be made withmore simplified electronics. However, in other embodiments, the system10 may comprise delivery device 12 without any one or more of the othercomponents of the system 10 shown in FIG. 1.

In the generalized system diagram of FIG. 1, the delivery device 12 andsensor or monitor 14 are secured to a patient-user. The locations atwhich those components are secured to the patient-user in FIG. 1 areprovided only as a representative, non-limiting example. The deliverydevice 12 and sensor or monitor 14 may be secured at other locations onthe patient, and such locations may depend upon the type of treatment tobe administered by the system 10.

As described in further detail below, the delivery device 12 contains areservoir of infusion media and delivers the infusion media into thepatient's body in a controlled manner. The delivery device 12 may beconfigured to secure to the skin of a patient, in the manner of a patch,at a desired location on the patient. Control instructions and/or datamay be communicated between the delivery device 12, the sensor ormonitor 14, the CCD 16 and the computer 18, as described in more detailbelow.

An example of a patch-like delivery device 12 according to an embodimentof the invention is shown in FIG. 2. The delivery device 12 in FIG. 2includes a disposable portion 20 and a durable portion 22. Thedisposable portion 20 may include structural elements that ordinarilycontact the patient's skin or infusion media, during operation of thedelivery device 12. On the other hand, the durable portion 22 may haveelements (including electronics, motor components, linkage components,and the like) that do not ordinarily contact the patient or infusionmedia during operation of the delivery device 12. Thus, elements in thedurable portion 22 of the delivery device 12 are typically notcontaminated from contact with the patient or infusion media duringnormal operation of the delivery device 12.

In the illustrated embodiment, the disposable portion of the deliverydevice 12 comprises a disposable base 20 that supports a reservoir 24.The durable portion 22 may comprise a housing that secures onto the base20 and covers the reservoir 24. The durable portion 22 may house asuitable drive device, such as an electrically operated motor (not shownin FIG. 2), and drive linkage components (not shown in FIG. 2) fordriving fluid out of the reservoir. The durable portion 22 also mayhouse suitable control electronics (not shown in FIG. 2) for controllingthe operation of the drive device to drive fluid from the reservoir in acontrolled manner. Further embodiments may include communicationelectronics (not shown in FIG. 2) within the durable portion 22, forcommunicating with the sensor or monitor 14, the CCD 16, the computer 18and/or other components of the system 10.

The disposable base portion 20 has a bottom surface (facing downward andinto the page in FIG. 2) that is configured to secure to a patient'sskin at a desired location on the patient. A suitable adhesive may beemployed at the interface between the bottom surface of the base portion20 and the patient's skin, to adhere the base portion 22 to thepatient's skin. The adhesive may be provided on the bottom surface ofthe base portion 20, with a pealable cover layer covering the adhesivematerial. In this manner, a patient-user may peal off the cover layer toexpose the adhesive material and then place the adhesive side of thebase portion 20 against the patient's skin.

The base portion 20 may include a suitable opening or port 23 forconnecting a hollow tube 25 to the reservoir, to convey infusion mediafrom the reservoir. One end of the tube 25 may have a suitable connector26, such as, but not limited to a Luer connector or a threaded capconnector having a hollow needle for coupling (in fluid-flowcommunication) to a corresponding connector 27 on the reservoir 24.Alternatively or in addition, the reservoir 24 may include a septum aspart of the connector 27, for receiving an end of a hollow needle. Theopening or port on the base portion 20 may be provided withcorresponding connector structure, such as, but not limited to a Luerconnector receptacle or a threaded receptacle shaped to receive athreaded cap connector. Other embodiments may employ other suitableconnectors or connection arrangements for connecting one end of the tube25 in fluid-flow communication with the reservoir 24.

The other end of the tube 25 may connected to a hollow needle 21 forpiercing the patient's skin and conveying infusion media into thepatient. The hollow needle 21 may be secured to the patient's skin, forexample, by manual application or with the assistance of an insertiontool, such as, but not limited to the insertion tool described in U.S.Patent Application Publication No. 2002/0022855, titled “InsertionDevice For An Insertion Set And Method Of Using The Same.” In otherembodiments, as described below, a hollow needle and insertion mechanismmay be included within the delivery device 12, so as to avoid the needfor a port 23, tube 25 and connector 26.

The durable portion 22 of the delivery device 12 includes a housingshell configured to mate with and secure to the disposable base portion20. The durable portion 22 and base portion 20 may be provided withcorrespondingly shaped grooves, notches, tabs or other suitable featuresthat allow the two parts to easily snap together, by manually pressingthe two portions together in a manner well known in the mechanical arts.In a similar manner, the durable portion 22 and base portion 20 may beseparated from each other by manually applying sufficient force tounsnap the two parts from each other. In further embodiments, a suitableseal, such as an o-ring seal, may be placed along the peripheral edge ofthe base portion 20 and/or the durable portion 22, so as to provide aseal against water between the base portion 20 and the durable portion22.

The durable portion 22 and base portion 20 may be made of suitably rigidmaterials that maintain their shape, yet provide sufficient flexibilityand resilience to effectively snap together and apart, as describedabove. The base 20 material may be selected for suitable compatibilitywith the patient's skin. For example, the base portion 20 and thedurable portion 22 of the delivery device 12 may be made of any suitableplastic, metal, composite material or the like. The base portion 20 maybe made of the same type of material or a different material relative tothe durable portion 22. The base portion and durable portions may bemanufactured by injection molding or other molding processes, machiningprocesses or combinations thereof.

For example, the base portion 20 may be made of a relatively flexiblematerial, such as a flexible silicon, plastic, rubber, synthetic rubberor the like. By forming the base portion of a material capable offlexing with the patient's skin, a greater level of patient comfort maybe achieved when the base portion is secured to the patient's skin.Also, a flexible base portion 20 can result in an increase in the siteoptions on the patient's body at which the base portion 20 may besecured.

In the embodiment illustrated in FIG. 2, the durable portion 20 of thedelivery device 12 is connected to a sensor 14, through a sensor lead29. The sensor 14 may comprise any suitable biological or environmentalsensing device, depending upon the nature of the treatment to beadministered by the delivery device 12. For example, in the context ofdelivering insulin to a diabetes patient, the sensor 14 may comprise ablood glucose sensor.

The sensor 14 may be an external sensor that secures to the patient'sskin or, in other embodiments, may be an implantable sensor that islocated in an implant site within the patient. In the illustratedexample of FIG. 2, the sensor 14 is an external sensor having adisposable needle pad 14′ that includes a needle for piercing thepatient's skin and enzymes and/or electronics reactive to a biologicalcondition, such as blood glucose level, of the patient. The disposableneedle pad 14′ may electrically contact electrical conductors in thelead 29, to convey electrical signals from the sensor 14 to suitablesensor electronics located within the durable portion 22 of the deliverydevice 12. The lead 29 may have any suitable length. In this manner, thedelivery device 12 may be provided with sensor data from a sensorsecured to the patient, at a site remote from the location at which thedelivery device 12 is secured to the patient.

While the embodiment shown in FIG. 2 includes a sensor 14 connected by alead 29 for providing sensor data to sensor electronics located withinthe durable portion 22 of the delivery device 12, other embodiments mayemploy a sensor 14 located within the delivery device 12, as describedbelow. Yet other embodiments may employ a sensor 14 having a transmitterfor communicating sensor data by a wireless communication link with toreceiver electronics located within the durable portion 22 of thedelivery device 12. The wireless connection between the sensor 14 andthe receiver electronics in the durable portion 22 of the deliverydevice 12 may comprise a radio frequency RF connection, an opticalconnection, or another wireless suitable communication link. Furtherembodiments need not employ a sensor and, instead, provide infusionmedia delivery functions without the use of sensor data.

As described above, by separating disposable elements of the deliverydevice 12 from durable elements, the disposable elements may be arrangedon the disposable base portion 20, while durable elements may bearranged within a separable durable portion 22. In this regard, afterone (or a prescribed number) of uses of the delivery device 12, thedisposable base portion 20 may be separated from the durable portion 22,so that the disposable base portion 20 may be disposed of in a propermanner. The durable portion 22 may, then, be mated with a new (un-used)disposable base portion 20 for further delivery operation with apatient.

The reservoir 24 may be supported by the disposable base portion 20 inany suitable manner. The reservoir may be provided as a cartridge orgenerally cylindrical canister for containing fluidic infusion media.For example, the base portion 20 may be provided with projections orstruts, or a trough feature for holding a cartridge-type reservoir in amanner that allows a user to readily remove the reservoir from the baseportion and re-install a new or refilled reservoir, when replacement orre-filling is needed, as described with respect to further embodimentsbelow. Alternatively, or in addition, the reservoir 24 may be secured tothe base portion 20 by a suitable adhesive or other coupling structure.The reservoir 24 has a port and may be supported by the base portion 20in a position at which a connector 26 may engage or otherwise come intofluid flow communication with the reservoir port, when the connector 26is connected to the port 23 on the base portion 20.

The durable portion 22 of the delivery device 12 may include a motor orother force-applying mechanism, for applying a force to the infusionmedia within the reservoir 24 to force fluidic infusion media out of thereservoir 24 and into the needle 27, for delivery to the patient. Forexample, an electrically driven motor may be mounted within the durableportion 22 with appropriate linkage for causing the motor to operablyengage a piston of the reservoir and drive the reservoir piston in adirection to cause the fluidic pressure within the reservoir to increaseand thereby force fluidic infusion media out of the reservoir port, intothe tube 25 and needle 27. The motor may be arranged within the durableportion 22 and the reservoir may be correspondingly arranged on thedisposable portion 20, such that the operable engagement of the motorwith the reservoir piston (e.g., through appropriate linkage) occursautomatically upon the patient-user snap fitting the durable portion 22onto the disposable portion 20 of the delivery device 12.

One example of a motor and reservoir configuration is shown in FIG. 3.In the embodiment of FIG. 3, the reservoir 24 (shown in cross-section)comprises a canister, for example, made of a suitable metal, plastic,ceramic, glass, composite material or the like, for containing a fluidicinfusion media. The canister reservoir 24 includes an opening 30,through which infusion media from inside of the reservoir may beexpelled from the reservoir in response to a force applied by a pistonplunger 32. As described in further embodiments below, the opening 30may contain a septum that is designed to be pierced by a needle.

The piston plunger 32 extends partially into the canister from theopposite side of the canister relative to the opening 30. The pistonplunger 32 may be made of a suitably rigid material, such as but notlimited to metal, plastic, ceramic, glass or composite material, and hasa head 34 that has an outside diameter of slightly less than the insidediameter of the canister portion of the reservoir. One or more seals,such as but not limited to o-ring type seals 36, may be arranged withinannular grooves provided on the piston plunger head 34. The o-ring seals36 may be made of any suitable material, including, but not limited torubber, plastic, metal, composite material or the like, where sucho-rings provide a sealing function for inhibiting the leakage ofinfusion media from the piston-plunger end of the reservoir 24. Thematerials from which the reservoir 24, piston plunger 32 and seal(s) 36are made are preferably selected for suitable strength and durabilitycharacteristics, as well as compatibility with the infusion media.

The piston plunger 32 in FIG. 3 includes a keyed or threaded portion 38,located external to the canister reservoir 24. The keyed or threadedportion 38 is provided with keys, key slots or threads that areconfigured to engage corresponding key slots, keys or threads on alinkage structure 40. In the illustrated example of FIG. 3, the linkagestructure 40 includes a keyed, slotted or threaded shaft 42, supportedby bearings 43 or other suitable structure for allowing rotation of theshaft 42 about its longitudinal axis. The bearings 43 may be mountedwithin the durable portion 22 of the delivery device 12, so as tosupport the shaft 42 for rotation within the durable portion 22.

A motor 44 is mechanically coupled to the shaft 42, to drive the shaftin a rotary motion about its axis in a controlled manner. The motor 44may be coupled to the shaft 42 through one or more suitable gears,belts, chains, drive shafts or other linkage structure. In theembodiment illustrated in FIG. 3, the motor 44 includes a drive gear 45,while the shaft 42 is provided with a further gear 46. A third gear 47is arranged between the drive gear 45 and the further gear 46, to conveyrotary drive force from the motor 44 to the shaft 42. Thus, the drivegear 45, the further gear 46 and the third gear 47 form a gear train fortransferring motor drive force to the shaft 42. In this manner, as themotor rotatably drives the motor drive shaft, the gear train transfersthe motor drive force to rotate the shaft 42, which is transferred to anaxial movement of the piston plunger 32 relative to the reservoir 24.

The motor 44, shaft 42 and gear train therebetween may be mounted withinthe durable portion 22 of the delivery device in a location at which thekeyed, slotted or threaded portion of the shaft 42 engages the slotted,keyed or threaded portion of the piston plunger 32, as shown in FIG. 3.In this manner, when the durable portion 22 is snap fitted onto thedisposable portion 20, the keyed, slotted or threaded portion of theshaft 42 automatically engages the slotted, keyed or threaded portion ofthe piston plunger 32 without requiring further user manipulation of theelements.

While not shown in FIG. 3, the motor 44 may be provided with electricalterminals for connection to a motor control circuit (not shown). Themotor control circuit may be mounted within the durable portion 22 ofthe delivery device, for controlling the operation of the motoraccording to a desired infusion delivery program or profile. A deliveryprogram or profile may be stored within a suitable electronic storagemedium located within the durable portion 22 and/or may be communicatedto the delivery device 12 from other sources, such as a CCD 16 or acomputer 18 (as shown in FIG. 1). Alternatively or in addition, themotor control circuit may control the motor to deliver one or morediscrete volumes of infusion media in response to delivery demandcontrol signals generated within the device 12 or communicated to thedevice 12 from other sources, such as a CCD 16 or a computer 18 (asshown in FIG. 1).

In the arrangement illustrated in FIG. 3, once the reservoir 24 has beensufficiently emptied or otherwise requires replacement, the patient-usermay simply unsnap and remove the durable portion 22 from the disposablebase portion 20 of the delivery device and replace the disposableportion 20 (including the reservoir) with a new disposable portionhaving a filled or re-filled reservoir 24. The durable portion 22 may besnap fitted onto the new disposable portion and the delivery device(including the new disposable portion) may be secured to the patient'sskin, as described above.

In a further embodiment, the reservoir 24 may be supported by the baseportion 20 in a manner that allows the reservoir 24 (and piston plunger32) to be removed from the remainder of the base portion 20 and disposedof or re-filled, and further allows a new or re-filled reservoir 24 (andpiston plunger 32) to be re-installed onto the base portion 20, whilethe base portion remains secured to the patient-user's skin. In thismanner, the reservoir may be removed and a new or re-filled reservoirmay be installed on the same base portion. The same base portion may beused for multiple new or re-filled reservoirs and, then, disposed ofafter a prescribed number of new or re-filled reservoirs have been usedon the base portion, while the same durable portion may be used formultiple base portion replacements.

The reservoir may be supported on the disposable base portion 20 by atrough structure (or other type of seat) formed on the base portion 20.In such an embodiment, the reservoir may be freely lifted off of thetrough structure (or other type of seat) by the patient-user, when thedurable portion 22 is removed from the base portion 20 of the deliverydevice 12, but is inhibited from lifting off of the trough structure byan obstructing part of the durable portion 22 when the durable portion22 is snap fitted onto the base portion 20. Alternatively, or inaddition, other manners of removably supporting the reservoir 24 on thebase portion 20 may be employed, including, but not limited to, strapsattached to the base portion, low strength adhesive material on the baseportion, or the like.

While the embodiment shown in FIG. 3 is one example of a manner ofcoupling a drive motor 44 to a reservoir 24, to drive infusion mediafrom the reservoir in a controlled manner, other suitable manners ofcoupling a drive motor 44 to a reservoir 24 may be employed inaccordance with other embodiments of the present invention, while stillallowing a disposable portion of a delivery device to be easilyremovable and replaceable relative to a durable portion of the deliverydevice. Further examples of drive motor coupling arrangements are shownin FIGS. 4-11, wherein components similar to those described above withrespect to FIG. 3 are provided with correspondingly similar referencenumbers.

The drive motor coupling arrangement of FIG. 4 includes a piston plunger32 that has a half-nut or single rack configuration. In particular, thepiston plunger 32 in FIG. 4 has a threaded rack 48 extending along thelongitudinal dimension of the piston plunger, from a location offsetfrom the center of the head 34. The motor 44 includes a rotatably drivendrive shaft on which a drive screw 49 is mounted for rotation with thedrive shaft. During operation, the drive screw 49 is arranged to engagethe threaded rack 48 and, upon rotation of the drive screw, provides anlinear movement of the piston plunger 32 relative to the reservoir 24.

The reservoir 24 in FIG. 4 may be supported on a base portion 20 of thedelivery device 12 (FIG. 1), in a manner as described above with respectto FIG. 3. Similarly, the motor 44, including the drive shaft and drivescrew 49 may be supported within the durable portion 22 of the deliverydevice 12. When the durable portion 22 is removed from the base portion20, the rack 48 may be easily disengaged from the drive screw 49 bysimply lifting the reservoir off of the base portion 20. A new orre-filled reservoir (and piston plunger 32) may be re-installed onto thebase portion 20 and readily engaged with the drive screw 49, by simplyaligning the threaded rack 48 with the drive screw 49 while placing thenew or re-filled reservoir onto the base portion 20. A trough or seatmay be included in the base portion 20, as described above, in alocation that aligns the threaded rack 48 with the drive screw 49, whenthe durable portion 22 of the delivery device is snap fitted onto thebase portion 20 of the delivery device.

A further drive motor coupling arrangement is shown in FIG. 5, whereinthe piston plunger 32 has a threaded rack 48 extending along thelongitudinal dimension of the piston plunger, from a location offsetfrom the center of the head 34, similar to the threaded rack 48 in FIG.4., However, in the arrangement shown in FIG. 5, the motor 44 isarranged such that the drive shaft of the motor is perpendicular to thelongitudinal, axial dimension of the piston plunger 32. The drive shaftof the motor 44 in FIG. 5 is provided with a pinion gear 50 that engagesthe threaded rack 48 of the piston plunger 32. In this manner, as themotor rotatably drives the motor drive shaft, the pinion gear 50 rotateswith the motor drive shaft to provide a linear movement of the pistonplunger 32 relative to the reservoir 24.

The reservoir 24 in FIG. 5 may be supported on a base portion 20 of thedelivery device 12 (FIG. 1), in a manner as described above with respectto FIGS. 3 and 4. Similarly, the motor 44, including the drive shaft andpinion gear 50 may be supported within the durable portion 22 of thedelivery device 12. When the durable portion 22 is removed from the baseportion 20, the rack 48 may be easily-disengaged from the pinion gear 50by simply lifting the reservoir off of the base portion 20. A new orre-filled reservoir (and piston plunger 32) may be re-installed onto thebase portion 20 and readily engaged with the pinion gear 50, by simplyaligning the threaded rack 48 with the pinion gear 50 while placing thenew or re-filled reservoir onto the base portion 20. A trough or seatmay be included in the base portion 20, as described above, in alocation that aligns the threaded rack 48 with the pinion gear 50 whenthe durable portion 22 of the delivery device is snap fitted onto thebase portion 20 of the delivery device.

A further drive motor coupling arrangement is shown in FIG. 6. Thearrangement in FIG. 6 is similar to that of FIG. 5, except that thepiston plunger 32 is provided with a double rack arrangement composed oftwo racks 60 as described above with respect to rack 48. In addition,the motor 62 in FIG. 5 is provided with two drive shafts, each driveshaft having a pinion gear 64 for engaging the racks 60 and operates ina manner similar to the single rack and pinion arrangement of FIG. 5. Inthe arrangement shown in FIG. 6, the pinion gears 64 are arrangedside-by-side, along the longitudinal or axial direction of the pistonplunger 32. FIG. 7 shows a configuration similar to FIG. 6, except thatthe pinion gears 64 are arranged adjacent each other along a directionperpendicular to the longitudinal or axial direction of the pistonplunger 32.

Yet a further drive motor coupling arrangement is shown in FIG. 8. Thearrangement of FIG. 8 is similar to that of FIG. 4, except that thepiston plunger 32 is provided with a hollow shaft portion 80 having athreaded interior. The drive screw 49 is configured to be threadablyinserted into the hollow shaft portion 80, such that threads on thedrive screw engage threads on the inner surface of the hollow shaft 80.In this manner, rotation of the drive shaft and drive screw 49 by themotor 44 provides a linear movement of the piston plunger 32 within thereservoir 24. In the embodiment shown in FIG. 8, one or more seals 80,such as o-ring seals 82, may be arranged around the hollow shaft portion80.

A further drive motor coupling arrangement is shown in FIGS. 9 and 10,wherein the motor 44 is provided with a threaded drive shaft screw 90.The arrangement of FIGS. 9 and 10 includes a piston plunger 92 having apiston head 34 similar to the piston head described above with respectto FIGS. 4-8. However, the piston plunger 92 in FIGS. 9 and 10 furtherincludes a pair of arm members 94 that extend from the head 34 in a Vconfiguration. Each arm member 94 includes a threaded foot portion 96extending toward the threaded drive shaft screw 90.

The arm members 94 are connected to or otherwise extended from thepiston head 34 in a manner that allows the arm members 94 to pivotslightly in the direction toward and away from the threaded drive screw90. By virtue of their pivoting motion, the arm members 94 may bepivoted such that the threaded foot portions 96 are brought into or outof engagement with the threaded drive screw 90. When the arm members 94are pivoted such that the foot portions 96 are out of engagement withthe threaded'shaft 90, as shown in FIG. 9, the reservoir 24 may beseparated from the motor 44 and removed from the delivery device 12.However, when the arm members 94 are pivoted such that the foot portions96 are brought into engagement with the threaded drive screw 90, asshown in FIG. 10, then rotation of the threaded drive screw by theaction of the motor 44 will result in a linear movement of the pistonhead 34 within the reservoir 24.

A pair of cam surfaces 98 may be arranged within the drive device 12 atlocations that engage the outer surface of the arm members 94, when thereservoir 24 and piston plunger are rotated, for example, in thedirection of the arrow 99 in FIG. 9. The cam surfaces 98 may be arrangedrelative to the reservoir 24, such that engagement of the arm members 94with the cam surfaces 98 causes the arm members 94 to pivot toward thethreaded drive screw to engage the foot portions 96 with the threadeddrive screw. The cam surfaces 98 may be formed as part of the structureof the base portion 20, the durable portion 22 or both.

Accordingly, during a reservoir canister replacement or refillingoperation, a patient-user may remove the durable portion 22 from thebase portion 20 of the delivery device to expose the reservoir canister24. The patient-user may, then, rotate the reservoir 24 in a directionto disengage the arm members 94 from the cam surfaces 98 and allow thefoot portions 96 of the arm members 94 to disengage from the threadeddrive shaft 90 (as shown in FIG. 9). In that position, the reservoir 24(including the piston plunger and arm members 94) may be lifted from thebase portion and either re-filled or replaced with a new reservoircartridge 24 (including piston plunger and arm members 94). The new orre-filled reservoir cartridge may be placed back into the base portion20 with the arm members 94 arranged out of engagement with the camsurfaces 98 (as shown in FIG. 9). Thereafter, the patient-user mayrotate the reservoir cartridge 24 in the direction of arrow 99, to bringthe arm members 94 into engagement with the cam surfaces 98 and causethe foot portions 96 to engage the threaded drive shaft 90 (as shown inFIG. 10).

A further drive motor coupling arrangement is shown in FIG. 11. Thecoupling arrangement in FIG. 11 is similar to that of FIG. 3, exceptthat the threaded portion of the piston plunger comprises a threadedscrew 100 extending from the piston head 34 and engaging a gear of thegear train. In particular, the gear train in the embodiment of FIG. 11includes a motor drive gear 101, a gear 102 engaging the motor drivegear and a shaft 104 coupling the gear 102 to a third gear 103. Thethird gear 103 is arranged to engage the threaded screw 100 such thatrotation of drive gear 101 by the motor 44 causes rotation of the gears102 and 103, which causes a linear movement of the shaft 100 and pistonhead 34 relative to the reservoir 24. The shaft 104 may be supported byone or more bearing structures 105 and may include one or more seals,such as o-ring seals 106.

The shaft 104 may be configured to rigidly connect gears 102 and 103,such that rotation of the gear 102 by the drive gear 101 results in alike rotation of the gear 103. Alternatively, the gear 103 may becoupled to the shaft 104 with a ratchet connection that allows the gearto be driven in one direction (such as the direction in which the pistonhead 34 would be moved toward the septum end of the reservoir toincrease pressure within the reservoir and cause infusion fluid to beexpelled from the septum end of the reservoir (provided the septum ofthe reservoir has been opened). On the other hand, the ratchetconnection of the gear 103 with the shaft 104 may allow the gear 103 tofreely rotate in the other direction (the direction for causing thepiston head 34 to move in the outward direction away from the septum endof the reservoir).

Thus, as described above, various arrangements for connecting a drivemotor 44 to a reservoir cartridge 24 may be employed to allow fluidicmedia within the reservoir cartridge to be delivered to a patient in acontrolled manner. The arrangements described above include a pistonplunger 32 for imparting a controlled force on the fluidic media withinthe reservoir 24, in response to the controlled drive force of a motor.However, other embodiments may employ other suitable arrangements forimparting a controlled force on the fluidic media, includingarrangements in which a rotary pump blade is mounted within or to thereservoir cartridge 24.

For example, FIG. 12 shows a cross-sectional view of an embodiment of apump assembly 110 for connection to a septum end of a reservoircartridge 24. The pump assembly 110 includes a housing portion 112 thatcontains a pump chamber 114. A rotary pump blade 116 is supported forrotation on a drive axle 118, within the pump chamber 114. The driveaxle 118 passes through a sealed opening in the side of the housing 112and is attached to a gear 120 located outside of the housing 112. Thegear 120 is engaged with a motor drive gear 122 coupled to the driveshaft of the motor 44, such that rotation of the motor drive shaft bythe motor 44 causes the gear 120 to drive the blade 116 in a rotarymotion within the pump chamber 114.

The housing 112 includes a receptacle 124 for having a size and shapefor receiving the septum end of a reservoir cartridge 24. A hollowneedle 126 is arranged with a sharp end located within the receptacle124 and facing toward the open end of the receptacle 124. The oppositeend of the hollow needle is provided in fluid flow communication withthe pump chamber 114. The pump chamber 114 is also provided in fluidflow communication with an outlet chamber in an outlet end 128 of thehousing 112.

The outlet end 128 of the housing 112 may include a port or othersuitable opening to convey fluidic material out of the outlet chamberend 128. In the embodiment shown in FIG. 12, the outlet end 128 of thehousing 112 includes a pair of septa 130 arranged to allow a needle topass through both septa 130. In this manner, a hollow needle 131 may bepushed through the septa 130 to align an inlet port 132 on the needle influid flow communication with the outlet chamber. The hollow needle 131thereby provides a fluid flow path for the fluid within the outletchamber end 128 of the housing 112 to exit the outlet chamber.

Thus, according to the arrangement shown in FIG. 12, a pump assembly 110may be coupled to a reservoir 24, by pushing the receptacle end 124 ofthe pump assembly housing 112 over the septum end of the reservoircartridge 24 until the hollow needle 126 pierces the septum 27 on thereservoir cartridge 24 and extends partially into the reservoir. As aresult, the interior of the reservoir 24 will be in fluid flowcommunication with the pump chamber 114. Thereafter, rotation of thepump blade 116 in a forward pumping direction will produce a negativepressure to draw fluid from the reservoir, through the hollow needle 126and into the pump chamber.

The action of the pump blade further causes fluid to be expelled fromthe pump chamber 114 and into the outlet chamber end 128 of the housing112, where the fluid is caused to flow into the needle port 132 andthrough the needle 131. As fluidic infusion media is pumped out of thereservoir 24, a moveable plunger 133 within the reservoir 24 may becaused to move toward the septum end of the reservoir by the negativepressure imparted by the pump assembly 110. The plunger 133 may beconfigured similar to the piston plunger head 34 described above and mayinclude one or more seals, such as o-ring seals, as described above withrespect to the piston plunger head 34. After the reservoir 24 has beensufficiently spent, the pump assembly housing 112 may be disengaged fromthe reservoir 24 by simply pulling the reservoir 24 and housing 112apart to disengage the needle 126 from the septum 27.

In the arrangement shown in FIG. 12, the needle 131 may be used in placeof the needle 21, tube 25 and connector 26 shown in FIG. 2. Inparticular, a reservoir 24 may be supported on a base member 20, asdescribed above and a pump assembly 110 may be connected to thereservoir 24, as described above with respect to FIG. 12. The baseportion 20 may be provided with an opening or pierceable wall inalignment with the tip of the needle 131, to allow the needle to passthrough the base member 20 and into the patient-user's skin under thebase member 20, when extended. In this manner, the needle 131 may beused to pierce the patient-user's skin and deliver infusion media to thepatient.

Alternatively, the needle 131 may be extended through a hollow cannula,such that upon piercing the patient-user's skin with the needle, an endof the hollow cannula is guided through the patient's skin by the needle131. Thereafter, the needle 131 may be removed, leaving the hollowcannula in place, with one end of the cannula located within the patientand the other end of the cannula located in the outlet chamber end 128of the pump assembly 110, to convey pumped fluid from the pump assembly110 into the patient.

The needle 131 may be provided with a head 134 having a surface on whicha force may be applied (downward directed force with respect to theorientation in FIG. 12), to move the needle 131 through the septa 130and into the patient's skin. The force may be applied to the needle head134 by manually pushing the needle head. For example, a patient-user maysecure the base member 20 to an appropriate location on thepatient-user's skin. With the reservoir 24 and pump assembly 110supported on the base member as described above, the patient-user mayapply a force onto the needle head 134 to extend the needle 131 (orneedle and cannula) through the septa 130, through the base portion 20and into the patient-user's skin. The durable portion 22 (containing themotor 44 and drive gear 122) may be snap fitted to the base portion 20in a position in which the motor 44 is aligned with the gear 120 on thereservoir 24. The motor 44 may be controlled by motor controlelectronics located within the durable portion 22 to drive the rotarypump blade to pump fluidic infusion media from the reservoir 24, throughthe needle 131 (or cannula) and into the patient in a controlled manner,for example, according to delivery instructions or a predefined deliveryprogram or profile.

Other suitable arrangements for supporting a reservoir 24 on a baseportion 20, coupling a needle (or cannula) to the reservoir andinserting the needle (or cannula) into a patient-user's skin are shownin FIGS. 13-24 and 28-30. Elements in FIGS. 13-24 and 28-30 that aresimilar to those described above with respect to FIGS. 1-12 are numberedwith correspondingly similar reference numbers.

For example, FIG. 13 shows a partially exploded view of some of thecomponents of a delivery device 10, including a disposable base portion20, a durable portion 22 and a reservoir 24 as described above. Thepump, motor, linkage and electronics are not shown in FIG. 13, tosimplify the drawing. The reservoir 24 in FIG. 13 is supported in adisengaged position on the base by a trough-like structure 140. Thetrough 140 is positioned on a plurality of struts 142 (two on each sidefor a total of four in the embodiment of FIG. 13). The struts 142 arerelatively rigid, but have sufficient flexibility and resilience toallow the struts to provide a snap fit with the trough, as describedbelow. The struts 142 may be formed integral with the base portion 20 ormay be separate elements that are attached to the base portion 20 by anysuitable attachment mechanism. The struts 142 may be made of anysuitable material, including but not limited to the material of the base20, metal, plastic, composite material or the like.

With reference to FIG. 14, each strut 142 has a surface 144 on which thetrough structure 140 (FIG. 13) rests, when in a disengaged position. Inthe illustrated embodiment, the surface 144 is angled to enhance theability of the trough structure 140 to move into an engaged position (asdescribed below with reference to FIG. 16). In other embodiments, thesurface 144 may have a curvature or other suitable shape that allows thetrough structure 140 to move into an engaged position. Each strut 142also has a stop surface 146, for abutting an edge surface 148 of thetrough structure 140, upon the trough structure 140 being moved into anengaged position (as shown in FIG. 16).

The trough-like structure 140 includes a platform portion 150 abutted bya spring 152. The spring 152 may comprise a coil spring arranged betweenthe base 20 and the platform portion 150, to bias the platform portion150 toward the disengaged position (as shown in FIG. 13). A hollowneedle 154 is secured to and extended through the platform portion 150,such that one end of the needle 154 is directed toward the septum end ofa reservoir canister 24, when the reservoir canister 24 is placed in thetrough-like structure 140. The opposite end of the needle 131 isdirected toward the disposable base 20. The disposable base 20 mayinclude an opening or pierceable wall portion in alignment with theneedle end directed toward the base 20, to allow the needle end to passthrough the base 20 and into the patient-user's skin, when the reservoirand trough-like structure is moved into an engaged position.

More specifically, with the configuration of FIGS. 13-16, a patient-usermay secure the disposable base portion to the patient-user's skin, asdescribed above. A reservoir canister 24 having a septum end 27 isarranged on the trough-like structure 140, with the septum 27 inalignment with the exposed end (upward facing end in FIG. 13) of theneedle 154. By manually pressing the reservoir canister 24 toward thedisposable base 20, the trough-like structure 140 may be moved from itsposition shown in FIG. 13, toward the base 20 and into the engagedposition shown in FIG. 16, against the force of the spring 152. Duringmovement of the trough-like structure 140 between the disengagedposition (FIG. 13) and the engaged position (FIG. 16), the struts 142flex slightly to allow the trough-like structure to move to a positionunder the stop surfaces 146 of the struts 142. When in the engagedposition (FIG. 16), the stop surfaces 146 of the struts 142 engage theedge surfaces 148 of the trough-like structure 140, to lock thetrough-like structure in an engaged position.

The action of moving the reservoir canister 24 into an engagementposition also effects the placement of the needle 154 into an engagementposition. Initially, the end of the reservoir end of the needle 154 maybe arranged adjacent or even partially extended into the septum 27 ofthe reservoir canister 24. By manually engaging or pressing thereservoir canister 24 onto the trough-like structure 140, the hollowneedle 154 is caused to pierce the septum 27 of the reservoir canister24 and come into flow communication with fluidic media within thereservoir canister 24. By applying a greater manual pressure onto thereservoir canister 24, the reservoir canister 24 and the trough-likestructure 140 are caused to move from the disengaged position (FIG. 13)into the engaged position (FIG. 16). At the same time, the needle 154 ismoved with the trough-like structure 140, to cause the lower end of theneedle to pass through the base portion 20 and into the patient-user'sskin.

When the trough-like structure 140 reaches the engaged position (FIG.16), the struts 142 snap into position over the edge 148 of thetrough-like structure 140. Thus, in the engaged position (FIG. 16), thespring 152 is compressed, the trough-like structure 140 is locked inplace by the struts. In addition, when in the engaged position, thehollow needle 154 is located with one end of the needle in fluid flowcommunication with the interior of the reservoir canister 24 and theother end of the needle inserted into the patient, as shown in FIG. 15.Once the reservoir canister 24 and trough-like structure 140 are in theengaged position (FIG. 16), the durable portion 22 may be snap fitted tothe base portion 20 so as to engage a motor with the reservoir canister24 for driving fluid from the reservoir canister 24 in a controlledmanner, as described above.

FIGS. 17 and 18 show another configuration example for moving a hollowneedle (or cannula) into an engagement position, in which the needle (orcannula) is in flow communication with the reservoir canister 24 and hasan end located within the patient-user.

In the configuration shown in FIGS. 17 and 18, a spring-biased needle170 is surrounded by a coil spring 172 and extends from a spring headmember 174. When the spring 172 is compressed (as shown in FIG. 17), theneedle 170 is in a retracted position in which the sharp end of theneedle is positioned adjacent (or even slightly piercing) the septum end27 of a reservoir canister 24. When the spring 172 is in theuncompressed or partially uncompressed state (as shown in FIG. 18), theneedle 170 is moved through the septum 27 of the reservoir canister 24,through the base portion 20, and into a patient-user's skin.

The disposable base portion 20 may be provided with one or more latchmembers 176 that may be positioned to abut the spring head member 174,when the spring 172 is in the retracted position, to hold the spring 172(and needle 170) in the retracted position shown in FIG. 17. The latchmember(s) 176 may be manually moveable or flexible to selectivelydisengage from the spring head member 174 and allow the spring to expandand move the needle 170 into the extended or engaged position of FIG.18. The needle 170 may comprise a hollow needle having a side portlocated in a position that comes into flow communication with the insidevolume of the reservoir canister 24 when the needle 170 is positioned inthe extended or engaged position (FIG. 18). Alternatively, a cannula maybe positioned on the needle 170 such that moving the needle into theextended or engaged position (FIG. 18) moves one end of the cannula intoflow communication with the interior of the reservoir canister 24 andthe other end of the cannula into the patient-user. Thereafter, theneedle 170 may be removed, leaving the cannula in place.

In one example, each latch member 176 may comprise a pivotal member thatis supported on a strut or other support structure (not shown) of thebase portion 20 for pivotal motion between a latched position (FIG. 17)and an unlatched position (FIG. 18). Each latch member 176 may have amanually operable portion 178 that is arranged to allow a user toselectively apply a manual force to selectively disengage the latchmember 176 from the spring head member 174. In the embodiment of FIGS.17 and 18, two latch members 176 are provided, such that thepatient-user must release both latch members 176 at the same time tocause the spring 172 and needle 170 to move from the retracted position(FIG. 17) to the extended or engaged position (FIG. 18).

Yet another configuration example for moving a hollow needle (orcannula) into an engagement position is shown with respect to FIGS.19-22. In the configuration shown in FIGS. 19-22, the reservoir canister24 is provided with a head section 190 having an internal flow passage192 and a septum 194. The internal flow passage 192 has one end in fluidflow communication with the interior of the reservoir canister 24. Aspring-biased needle 196 is surrounded by a coil spring 198 and extendsfrom a spring head member 199. When the spring 198 is compressed (asshown in FIG. 19), the needle 196 is in a retracted position in whichthe sharp end of the needle is positioned adjacent (or even slightlypiercing) the septum 194 of a reservoir canister 24. When the spring 198is in the uncompressed or partially uncompressed state (as shown inFIGS. 20 and 21), the needle 196 is moved through the septum 194 of thereservoir canister 24, through a portion of the flow passage 192,through the base portion 20, and into a patient-user's skin.

A latch member 200 has a catch hook or surface 202 that may bepositioned to abut the spring head member 199, when the spring 198 is inthe retracted position, to hold the spring 198 (and needle 196) in theretracted position shown in FIG. 19. The latch member 200 may bemanually moveable to selectively disengage the catch surface 202 fromthe spring head member 199 and allow the spring to expand and move theneedle 196 into the extended or engaged position of FIGS. 20 and 21. Theneedle 196 may comprise a hollow needle having a side port located in aposition that comes into flow communication with the flow passage 192and, thus, the inside volume of the reservoir canister 24, when theneedle 196 is positioned in the extended or engaged position (FIGS. 20and 21). Alternatively, a cannula may be positioned on the needle 196such that moving the needle into the extended or engaged position (FIGS.20 and 21) moves one end of the cannula into flow communication with theinterior of the reservoir canister 24 and the other end of the cannulainto the patient-user. Thereafter, the needle 196 may be removed,leaving the cannula in place.

The latch member 200 in FIGS. 19-22 is supported for rotation movementon the reservoir canister head 190. The latch member 200 may connect toor include a valve portion 204 located within the flow passage 192. Inthe illustrated embodiment, the valve portion 204 comprises a rotaryvalve having a pass-through passage that aligns with the flow passage192, when the valve portion 204 is rotated into an open position (asshown in FIGS. 20 and 21). However, when the valve portion 204 isrotated into a closed position (as shown in FIG. 19), the pass-throughpassage in the valve portion 204 is not aligned with the flow passage192 (and, instead, a solid wall of the valve portion 204 blocks the flowpassage 192), such that fluid flow from the reservoir canister 24 isinhibited. The latch member 200 may include a handle 206 that allows apatient-user to readily rotate the latch member between the positionsshown in FIGS. 19 and 21. The latch member 200 may be separable from thevalve portion 204, such that, once the valve member 204 is rotated intoan open position (FIG. 20), the latch member 200 may be further rotatedto lock the valve member 204 into the open state and to detach the latchmember 200 from the valve member 204 (as shown in FIG. 21).

Thus, according to the configuration shown in FIGS. 19-22, apatient-user may secure the disposable base portion 20 onto thepatient-user's skin. The patient-user then may grip the handle 206 androtate the latch member 200 from a position as shown in FIG. 19 into aposition as shown in FIG. 20, for example, by turning the handle 206 inthe direction of arrow 208. As the latch member 200 is rotated, thecatch 202 is caused to align with a notch 210 in the spring head 199 andreleases the spring head 199. Upon release of the spring head 199, thespring 198 causes the spring head 199 and needle 196 (or needle 196 andsurrounding cannula) to move into the extended or engaged position(shown in FIG. 20). As the needle 196 moves to the extended position(FIG. 20), the needle is passed through the septum 194, a portion of theflow passage 192, the base member 20 and a the patient-user's skin in asingle, quick motion.

The patient-user may, then, rotate the handle 206 further in thedirection of arrow 212 into a lock position as shown in FIG. 21. In thelocked position, the latch member 200 becomes disengaged from the valvemember 204. If the needle 196 is used as an introducer needle, forintroducing a cannula, the needle 196 may be removed, once the cannulahas been set in place. Thus, after rotating the latch member 200 intothe position shown in FIG. 21, the latch member (including theintroducer needle 196) may be pulled out of the delivery device anddisposed of (as shown in FIG. 22).

In one embodiment, the latch member 200 may be accessible to thepatient-user, when the durable portion 22 is removed from the baseportion 20 of the delivery device 12. In other embodiments, the latchmember 200 may extend through an opening in the durable portion 22 so asto be accessible to a patient-user after the durable portion 22 has beenfitted onto the base portion 20, as shown in FIG. 22.

Yet other embodiments may employ a more simplified manner of positioninga needle (or needle and cannula) into the extended or engaged positiondiscussed above. For example, FIGS. 23 and 24 show an arrangementsimilar to that of FIG. 11, except that a simple needle hub member thatextends through the durable portion 22 is used. In the configuration ofFIGS. 23 and 24, a needle hub comprises a needle 220 for piercing aseptum of a reservoir canister 24 as described above. The durableportion 22 of the delivery device 12 is provided with an opening 222through which the needle 220 may be inserted. The opening 222 is alignedwith the septum of the reservoir cansister 24 (not in view in FIGS. 23and 24) located on the disposable portion 20 of the delivery device 12.

The needle 220 may comprise a hollow needle having a side port locatedin a position that comes into flow communication with the interior ofthe reservoir canister 24 (not in view in FIGS. 23 and 24) when theneedle 220 is positioned in the extended or engaged position (FIG. 23).Alternatively, a cannula may be positioned on the needle 220 such thatmoving the needle into the extended or engaged position (FIG. 23) movesone end of the cannula into flow communication with the interior of thereservoir canister 24 and the other end of the cannula into thepatient-user. Thereafter, the needle 220 may be removed, leaving thecannula in place (as shown in FIGS. 24).

Various aspects of the multiple embodiments described above may beemployed independently or in combinations thereof. For example, any oneof the various configurations described herein for coupling a motor 44to a reservoir 24 to drive fluid from the reservoir in a controlledmanner may be employed with any one of the various configurationsdescribed herein for moving a needle into an engagement position toeffect a flow communication between the reservoir 24 and thepatient-user.

Significant advantages can be obtained from various embodiments andcombinations described herein, wherein a delivery device includes adisposable portion that secures to a patient-user's skin and holdscomponents that come into contact with the infusion media (such as thereservoir), and a durable portion that includes a drive motor andsuitable electronics. Expensive components contained in the durableportion of the delivery device may be used over again, while thedisposable portion of the delivery device may be readily disposed ofafter one (or a prescribed number) of uses. By simplifying the manner inwhich the disposable portion of the delivery device can be replaced andby simplifying the manner in which the delivery device can bere-activate after replacing a disposable portion, a greater number ofpatients will be able to use and benefit from such delivery devices

To further simplify the use and operation of delivery devices asdescribed herein, such delivery devices may be configured in a manner tosimplify the ability to remove the disposable base portion 20 from thepatient-user's skin. In the examples described above, the disposablebase portion 20 may be secured to a user's skin by use of a suitableadhesive. However, if the adhesive is very strong, the patient-user mayhave difficulty (and, even, pain) when trying to pull or peal the baseportion 20 off of the patient-user's skin. Accordingly, in oneembodiment, the adhesive applied to the skin-contacting surface of thedisposable base portion 20 is provided in selective locations (insteadof across the entire surface). Such locations may be selected to providesuitable adhering qualities, such as locations around the position atwhich the needle passes through the base portion 20.

Alternatively, or in addition, adhesive material may be applied toperipheral regions of the base portion 20, while leaving some or all ofthe central region of the base portion 20 free of adhesive. One exampleof an adhesive pattern on the bottom (skin-facing) surface of the baseportion 20 is shown in FIG. 25. In FIG. 25, an adhesive pattern is shownin cross-hatching and includes adhesive 230 disposed along the outerperipheral edge of the base portion 20 and further adhesive 232 around aneedle opening 234 in the base portion. However, a large part of thecentral region 236 of the base portion 20 is free of adhesive. In thisregard, once a patient-user is able to remove or peal off an edge of thebase portion 20 from the patient-user's skin, the rest of the baseportion 20 can be pealed off of the skin with reduced force relative toa base portion 20 that is fully covered with adhesive.

In yet a further embodiment, an agent may be applied to dissolve theadhesive or otherwise reduce the adhering qualities of the adhesive, aspart of a procedure for removing a base portion 20 from a patient-user'sskin. The particular adhesive releasing agent employed may depend uponthe type of adhesive and, in some contexts, may be water or an aqueoussolution. The releasing agent may be formed in a gel, so as to avoidexcessive running of the agent, when it is applied. The agent may beapplied in various manners, including a spray applicator. In theconfiguration shown in FIG. 26, the delivery device 12 is provided witha reservoir 260, such as a flexible container or bladder, containing anadhesive releasing agent. The reservoir 260 may be mechanically coupledto an actuator button 262 that may be manually operated (e.g., pressed)to apply pressure onto the flexible container or bladder 260 to causethe agent within the container 260 to be released.

A network of tubes or conduits 264 may be connected to an outlet openingon the container or bladder 260, to direct the adhesive releasing agentto appropriate dispensing locations around the base portion 20, uponapplication of a suitable pressure on the container or bladder 260. Thebase portion 20 may be provided with openings or may be suitably porousto allow releasing agent from the network of tubes or conduits 164 topass through the base portion 20 to act upon adhesive material disposedbetween the base portion 20 and the patient-users skin. In embodimentsin which the adhesive material is provided in specified locations (asshown in FIG. 25), the network of tubes or conduits 264 may beconfigured to direct the releasing agent to those specified locations.For example, in connection with the adhesive pattern shown in FIG. 25, anetwork of tubes or conduits 164 may be configured to dispense theadhesive releasing agent to the outer peripheral edges of the baseportion 20 and to an area surrounding the needle opening 234 in the baseportion 20.

In further embodiments, the base portion 20 may be made of a relativelyflexible material, such as, but not limited to, a silicon rubber,flexible plastic, or the like, wherein the flexible nature of thematerial allows a patient-user to more easily peal off the base portion20 from the patient-user's skin. In particular, with a flexible baseportion 20, the patient-user may peal off an edge of the base portion 20from the patient-user's skin and, then bend the edge upward and acrossthe rest of the base portion 20, to provide a pull surface for pealingthe remainder of the base portion 20 off of the patient-user's skin.

In this manner, the base portion 20 may be readily pealed off of thepatient-user's skin and disposed of, after a suitable period of use. Thedurable portion 22 of the delivery device 12 may be snap fitted to a newbase portion 20 to continue the patient-user's treatment. As describedabove, the durable portion 22 may contain components, such as the drivemotor 44, linkage components for linking the drive motor to a reservoir,and electronics for controlling the drive motor to provide a controlleddelivery of infusion media. The drive motor 44 may be any suitable motorthat may be electronically controlled, including, but not limited to astepper motor, brushless motor, or the like.

While the electronics for operating the delivery device 12 may takevarious forms, one example embodiment of an electronics system 270 isshown in FIG. 27, wherein a processor 271 is configured or otherwiseprogrammed to provide functions described herein. The processor 271 maybe electronically connected to a motor control circuit 272 forcontrolling the operation of the motor 44. The motor 44 may becontrolled to operate (drive fluid from the reservoir) in accordancewith delivery program or profile data stored in an electronic storagedevice 274 connected to or otherwise associated with the processor 271.Alternatively or in addition, the processor 271 may respond to manualinputs, for example, from a manually operated button or other inputdevice 276 on the delivery device 12, to control the motor 44 (throughthe motor control circuit 272). As a further alternative or addition,the processor 271 may respond to inputs received by receiver electronics278 from, for example, a CCD 16 or computer 18 (FIG. 1) to control themotor 44 (through the motor control circuit 272). The processor 270 maybe connected to a sensor or monitor 14 to receive data representing asensed condition (such as, but not limited to, a blood glucose levelcondition). The delivery device 12 may include a display device 280 fordisplaying information to the patient-user, where the processor 271 maybe connected to control the display device 280. Suitable programs forcontrolling the processor 270 may be stored in the storage device 274 orother storage medium associated with the processor. A power source (notshown in FIG. 27), such as a battery, may be connected to variouscomponents of the electronic circuit and motor 44 shown in FIG. 27, to

A partially exploded view of a delivery device 12 in accordance with afurther embodiment of the invention is shown in FIG. 28, wherein adurable portion 22 of the delivery device contains electronics 270, apower source 280 for the electronics and a motor 44, as described above.The delivery device 12 in FIG. 28 also includes a disposable baseportion 20 on which a reservoir canister 24 may be supported, asdescribed above. An introducer needle 281 has a handle portion 282 andis positioned to allow the needle to be passed through the septum 27 ofthe reservoir 24, when the reservoir 24 is supported on the base portion20, similar to the needle arrangement described above with respect toFIGS. 23 and 24. However, in addition to a introducer needle, thedelivery device 12 in FIG. 28 also includes a second needle 284connected to sensor electronics. For example, the second needle 284 maybe connected to electronics that produce an electronic signalrepresentative of a sensed biological state, such as, but not limitedto, blood glucose level. In this manner, the delivery device 12 mayinclude an on-board sensor (such as an on-board continuous blood glucosesensor that provides continuous sensor data). In further embodiments,other types of sensor electronics may be included in the delivery deviceto provide sensing data. Such sensors may comprise, but are not limitedto, infrared or other forms of spectral analysis sensors (wherein thebase portion 20 may be provided with an opening or window through whichinfrared or other radiated beams may pass to access the patient's skinbelow the base portion.

The electronic signal may be provided to the electronics 270, through anelectrical coupling 286. The electronics 270 may include suitableelectronics for processing the sensor signal. As described above, theneedles 281 and 284 may be hollow needles that perform the fluidcommunication function, once inserted into the patient-user.Alternatively, the needles 281 and 284 may be introducer needles thatintroduce a cannula for providing the fluid communication function,after which the needles may be removed, leaving the cannula in place.FIGS. 29 and 30 provide additional views of an embodiment similar tothat of FIG. 28.

While embodiments described above have been illustrated in the drawingswith needles configured in common straight, linear configurations, theabove embodiments may be employed with needle configurations designed toreduce physical stress on the patient. For example, once a deliverydevice has been secured to a patient-user, a needle (or canulla) isextended into the user's skin, as describe above. With the deliverydevice adhered to the surface of the skin, it is possible that thedelivery device will move slightly relative to the needle point site, asthe patient-user moves and as the patient-user's skin moves and flexes.The movement of the delivery device while the needle is extended intothe patient-user's skin can apply a physical strain on the needle and,thereby cause the needle tip to move within the patient, resulting inphysical discomfort to the patient.

To minimize such discomfort, a needle configuration may be employed,wherein the needle is configured to minimize the transfer of movement tothe needle tip. For example, by forming a needle with multiple angles(such as multiple perpendicular angles) along its length, the transferof motion occurring on one end of the needle to the other end of theneedle can be reduced. Example needle configurations with such multipleangles are shown in FIGS. 30, 31 and 32, respectively. The needle 300 inFIG. 30 has two right-angle bends. The bends in combination with theflexible nature of the needle material result in dampening movements ofthe reservoir end of the needle 300 with respect to the sharp end(patient-user end) of the needle. Similarly, the needle 302 in FIG. 31includes four right-angle bends. The needle 303 in FIG. 32 includes tworight angle bends. Other configurations with angled bends, loops,spirals or the like may be employed to help dampen the transfer ofmotion from one end of the needle to the other. Further example ofneedle shapes are shown in FIGS. 33-36.

While embodiments described above employ a electrically operated pump 44connected to a reservoir canister 24, other embodiments may employ othermanners of storing infusion media and selectively dispensing theinfusion media to the patient, including, but not limited to flexiblebellows reservoirs, bladders, syringes or peristaltic pump devices.

Thus according to embodiments described above, an at-site deliverysystem could be fully disposable utilizing either a user filledreservoir or a pre-filled cartridge to deliver insulin. Alternatively,the at-site delivery system could be made of two parts, disposableportion and non-disposable portion. The disposable portion could containall materials that are in direct contact with the medication such asreservoir body, reservoir piston, septum systems and injection needle.The non-disposable portion could contain significantly the materialsthat are not in contact with the medication including the drive system,pressure or force sensing system, battery, electronics, display, andnon-disposable housing. The pump could be designed such that thedisposable portion (user filled or pre-filled cartridge) is insertedinto the non-disposable portion. In this manner, the adhesive to attachthe pump would be placed on the non-disposable pump portion.Alternatively, the disposable portion could contain the bottom plate andmounting adhesive.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that theinvention is not limited to the particular embodiments shown anddescribed and that changes and modifications may be made withoutdeparting from the spirit and scope of the claimed invention.

1. A delivery device for delivering an infusion media to a user, thedevice comprising: a first housing portion adapted to be secured to auser; a second housing portion configured to be selectively engaged withand disengaged from the first housing portion to allow disposal of thefirst housing portion without disposing of the second housing portion; areservoir for containing infusion media supported on the first housingportion, the reservoir comprising a container having an interior spacefor containing an initial volume of infusion media and a moveable memberdisposed at least partially within the container and moveable forvarying the interior space of the container to drive one or morediscrete volumes of infusion medium from the initial volume of infusionmedium in the interior space of the container, wherein each discretevolume is less than the initial volume; electrical control circuitry anda drive device contained in the second housing portion, wherein theelectrical control circuitry controls the delivery of infusion mediafrom the reservoir to the user and the drive device is coupled to adrive linkage for selectively driving the drive linkage in a drivedirection under control of the electrical control circuitry; wherein thedrive linkage operatively couples the drive device to the moveablemember of the reservoir to selectively move the moveable member tochange the interior space of the container of the reservoir and driveinfusion media from the reservoir under control of the electricalcontrol circuitry when the second housing portion is engaged with thefirst housing portion and the drive linkage is selectively driven in thedrive direction by the drive device.
 2. A delivery device according toclaim 1, wherein the drive device comprises an electrical motor.
 3. Adelivery device according to claim 1, wherein the drive linkageoperatively de-couples the drive device from the moveable member of thereservoir when the second housing portion is disengaged from the firsthousing portion.
 4. A delivery device according to claim 1, the drivelinkage comprises a gear supported for rotation in a first direction;the moveable member of the reservoir comprises a plunger disposed withinthe container of the reservoir and a threaded shaft extending from theplunger, the threaded shaft arranged in the first housing portion in alocation for engagement with the gear of the drive linkage when thefirst and second housing portions are engaged together, and fordisengagement with the gear of the drive linkage when the first andsecond housing portions are disengaged and separated from each other. 5.A delivery device according to claim 1, wherein the drive devicecomprises a threaded drive shaft screw and wherein the moveable memberof the reservoir comprises a piston plunger moveable within thecontainer, the piston plunger having a pair of pivotal arm membersextending longitudinally out of the container in a V-configuration,wherein each arm member comprises a threaded foot portion extendingtoward the threaded drive shaft screw of the drive device, and whereinthe delivery device further comprises cam surfaces arranged relative tothe reservoir for pivoting the arm members toward the threaded screw toengage the threaded foot portions of the arm members with the threadedscrew.
 6. A delivery device according to claim 5, wherein: the reservoircontainer and the piston plunger are supported for rotation; the armmembers operatively couple with the drive shaft screw of the drivedevice when the reservoir container and the piston plunger are rotatedin a direction allowing the cam surfaces to engage the arm members andthe drive shaft screw and when the first housing portion and the secondhousing portion are engaged; and the arm members and the drive shaftscrew allow for separation of the reservoir and the drive device whenthe reservoir container and the piston plunger are rotated in adirection opposite to the direction that allows the cam surfaces toengage the arm members and the drive shaft screw and when the firsthousing portion and the second housing portion are disengaged.
 7. Adelivery device according to claim 1, the drive linkage comprises a gearsupported for rotation in a first direction; the moveable member of thereservoir comprises a shaft for engaging the gear of the drive linkagewhen the second housing portion is engaged with the first housingportion, the shaft being supported for linear motion in a firstdirection and is linearly moveable in the first direction upon the gearof the drive linkage engaging the shaft and the drive linkage beingselectively driven in the drive direction by the drive device.
 8. Adelivery device according to claim 7, wherein the gear of the drivelinkage operatively de-couples from the shaft of the reservoir when thesecond housing portion is disengaged from the first housing portion. 9.A delivery device according to claim 1, the drive linkage comprises apinion gear supported for rotation in a first direction; the moveablemember of the reservoir comprises a threaded shaft for engaging thepinion gear of the drive linkage when the second housing portion isengaged with the first housing portion, the threaded shaft beingsupported for linear motion in a first direction and is linearlymoveable in the first direction upon the pinion gear of the drivelinkage engaging the threaded shaft and the drive linkage beingselectively driven in the drive direction by the drive device.
 10. Adelivery device according to claim 9, wherein the pinion gear of thedrive linkage operatively de-couples from the threaded shaft of thereservoir when the second housing portion is disengaged from the firsthousing portion.
 11. A delivery device according to claim 1, wherein thedrive linkage is contained in the second housing portion.
 12. A deliverydevice according to claim 11, wherein the drive linkage comprises a geartrain and a threaded shaft attached to an outermost gear of the geartrain away from the drive device, wherein the gear train provides arotating action to the threaded shaft.
 13. A delivery device accordingto claim 11, wherein: the drive linkage comprises a threaded shaftcoupled to the drive device for rotation; the moveable member of thereservoir having one of the group consisting of a threaded seat, a keyedseat, and a slotted seat engageable with the threaded shaft of the drivelinkage; the seat on the moveable member of the reservoir operativelycouples with the threaded shaft of the drive device when the firsthousing portion and the second housing portion are engaged, and whereinthe threaded shaft is configured to separate from the seat of themoveable member when the first housing portion and the second housingportion are disengaged.
 14. A delivery device according to claim 11,wherein: the drive linkage comprises a shaft and pinion gear coupled tothe drive device for rotation of the pinion gear; and the moveablemember of the reservoir comprises a moveable plunger operatively coupledwith the pinion gear to move the plunger upon rotation of the piniongear.
 15. A delivery device according to claim 14, wherein the plungercomprises a single threaded rack that operatively couples to the piniongear to be moveably driven with rotation of the pinion gear by the drivedevice when the first housing portion and the second housing portion areengaged.
 16. A delivery device according to claim 11, wherein: the drivelinkage comprises two shafts and two pinion gears, each pinion gearcoupled to a respective shaft, the shafts further coupled to the drivedevice for rotation of the shafts and pinion gears; and the moveablemember of the reservoir comprises a moveable plunger disposed at leastpartially within the container and moveable to drive infusion media outof the container, the plunger being operatively coupled with the twopinion gears to move the plunger upon rotation of the pinion gears. 17.A delivery device according to claim 16, wherein the plunger comprisestwo threaded racks that operatively couple to the pinion gears to bemoveably driven with rotation of the pinion gears by the drive devicewhen the first housing portion and the second housing portion areengaged.
 18. A delivery device according to claim 11, wherein the drivelinkage further comprises a shaft having first and second ends and adrive screw, and wherein the first end of the shaft is coupled to thedrive device for rotation by the drive device, the second end of theshaft is coupled to the drive screw for rotation therewith and the drivescrew is coupled to the reservoir for driving infusion media from thereservoir upon rotation of the drive screw.
 19. A delivery deviceaccording to claim 18, wherein the moveable member of the reservoircomprises a piston plunger with a hollow, threaded interior along alongitudinal direction of the piston plunger, wherein the threadedinterior is threaded to correspond to the drive screw of the drivedevice, and wherein the threaded interior operatively couples with thedrive screw of the drive device when the first housing portion and thesecond housing portion are engaged.
 20. A delivery device according toclaim 18, wherein the moveable member of the reservoir comprises apiston plunger having a longitudinal dimension and a single rack havingthreads extending along the longitudinal dimension of the pistonplunger, wherein the threads of the single rack operatively couple withthe drive screw of the drive device for rotation therewith when thefirst housing portion and the second housing portion are engaged.
 21. Adelivery device for delivering an infusion media to a user, the devicecomprising: a first housing portion adapted to be secured to a user; asecond housing portion configured to be selectively engaged with anddisengaged from the first housing portion to allow disposal of the firsthousing portion without disposing of the second housing portion; areservoir for containing infusion media supported on the first housingportion, the reservoir comprising a container having an interior spacefor containing a volume of infusion media under atmospheric pressure anda moveable member disposed at least partially within the container andmoveable for varying the interior space of the container to increasepressure of infusion media within the interior space of the containerand drive infusion medium from the interior space of the container;electrical control circuitry and a drive device contained in the secondhousing portion, wherein the electrical control circuitry controls thedelivery of infusion media from the reservoir to the user and the drivedevice is coupled to a drive linkage for selectively driving the drivelinkage in a drive direction under control of the electrical controlcircuitry; wherein the drive linkage operatively couples the drivedevice to the moveable member of the reservoir to selectively move themoveable member to change the interior space of the container of thereservoir and drive infusion media from the reservoir under control ofthe electrical control circuitry when the second housing portion isengaged with the first housing portion and the drive linkage isselectively driven in a drive direction by the drive device.
 22. Amethod for delivering an infusion media to a user, the methodcomprising: securing a first housing portion to a user; attaching asecond housing portion to the first housing portion in a manner thatallows a user to selectively detach the second housing portion from thefirst housing portion; supporting a reservoir for containing infusionmedia on the first housing portion, the reservoir comprising a containerhaving an interior space for containing an initial volume of infusionmedia and a moveable member disposed at least partially within thecontainer and moveable for varying the interior space of the containerto drive one or more discrete volumes of infusion medium from theinitial volume of infusion medium in the interior space of thecontainer, wherein each discrete volume is less than the initial volume;containing electrical control circuitry and a drive device in the secondhousing portion; coupling the drive device to a drive linkage forselectively driving the drive linkage in a drive direction under controlof the electrical control circuitry; and operatively coupling the drivedevice to the moveable member of the reservoir via the drive linkage, toselectively move the movaeable member to change the interior space ofthe container of the reservoir and drive infusion media from thereservoir to the user under control of the electrical control circuitrywhen the second housing portion and the first housing portion areengaged and the drive linkage is selectively driven in the drivedirection by the drive device.
 23. A method according to claim 22,wherein the drive device comprises an electrical motor.
 24. A methodaccording to claim 22, further comprising: containing the drive linkagein the second housing portion; and decoupling the drive device from themoveable member of the reservoir when the second housing portion isdisengaged and separated from the first housing portion.
 25. A methodaccording to claim 14, wherein the drive linkage comprises a gear trainand a threaded shaft attached to an outermost gear of the gear trainaway from the drive device, and wherein the method further comprisesrotating the gear train with the drive device and rotating the threadedshaft with the gear train.
 26. A method according to claim 14, wherein;containing a drive linkage in the second housing comprises coupling athreaded shaft to the drive device for rotation by the drive device; themoveable member of the reservoir having one of the group consisting of athreaded seat, a keyed seat, and a slotted seat engageable with thethreaded shaft of the drive device; operatively coupling the seat on themoveable member of the reservoir with the threaded shaft when the firsthousing portion and the second housing portion are engaged, andseparating the threaded shaft from the seat of the moveable member whenthe first housing portion and the second housing portion are disengaged.27. A method according to claim 24, wherein: containing a drive linkagein the second housing portion comprises containing a shaft having apinion gear on one end in the second housing portion and coupling thepinion gear to the drive device for rotation of the pinion gear by thedrive device; and the moveable member of the reservoir comprises amoveable plunger on the first housing portion, the moveable plungerlocated at least partially within the container and moveable to driveinfusion media out of the container; and operatively coupling themoveable plunger with the pinion gear to move the plunger upon rotationof the pinion gear.
 28. A method according to claim 27, wherein theplunger comprises a single threaded rack and wherein operativelycoupling the moveable plunger with the pinion gear comprises engagingthe pinion gear and the single threaded rack and moving the singlethreaded rack of the plunger with rotation of the pinion gear by thedrive device when the first housing portion and the second housingportion are engaged.
 29. A method according to claim 24, wherein:containing a drive linkage in the second housing portion comprisescontaining two shafts and two pinion gears in the second housing portionwith each pinion gear coupled to a respective shaft, and coupling theshafts to the drive device for rotation of the shafts and pinion gears;and the moveable member of the reservoir comprises a moveable plunger onthe first housing portion, the moveable plunger being located at leastpartially within the container and moveable to drive infusion media outof the container; and operatively coupling the moveable plunger to thetwo pinion gears to move the plunger upon rotation of the pinion gears.30. A method according to claim 29, wherein the plunger comprises twothreaded racks that operatively couple to the pinion gears to bemoveably driven with rotation of the pinion gears by the drive devicewhen the first housing portion and the second housing portion areengaged.
 31. A method according to claim 24, wherein containing a drivedevice and drive linkage comprises containing a threaded drive shaftscrew in the second housing portion and wherein the moveable member ofthe reservoir comprises a piston plunger on the first housing portion,the piston plunger being moveable within the container, the pistonplunger having a pair of pivotal arm members extending longitudinallyout of the container in a V-configuration, wherein each arm membercomprises a threaded foot portion extending toward the threaded driveshaft screw of the drive device, and wherein the method furthercomprises supporting cam surfaces relative to the threaded screw forcontacting and pivoting the arm members toward the threaded screw toselectively engage the threaded foot portions of the arm members withthe threaded screw.
 32. A method according to claim 31, furthercomprising: supporting the reservoir container and the piston plungerfor rotation; operatively coupling the arm members with the drive shaftscrew of the drive device when the reservoir and the piston plunger arerotated in a direction allowing the cam surfaces to engage the armmembers and the drive shaft screw and when the first housing portion andthe second housing portion are engaged; and separating the arm membersand the drive shaft screw when the reservoir and the piston plunger arerotated in a direction opposite to the direction that allows the camsurfaces to engage the arm members and the drive shaft screw and whenthe first housing portion and the second housing portion are disengaged.33. A method according to claim 24, wherein containing a drive linkagein the second housing portion comprises: containing a shaft having and adrive screw in the second housing portion; coupling the shaft to thedrive device for rotation by the drive device; coupling the shaft to thedrive screw for rotation therewith; and coupling the drive screw to thereservoir for driving infusion media from the reservoir upon rotation ofthe drive screw.
 34. A method according to claim 33, wherein themoveable member of the reservoir comprises a piston plunger having alongitudinal dimension and a single rack having threads extending alongthe longitudinal dimension, wherein the method further comprisescoupling the threads of the single rack operatively with the drive screwfor rotation therewith when the first housing portion and the secondhousing portion are engaged.
 35. A method according to claim 33, whereinthe moveable member of the reservoir comprises a piston plunger with ahollow, threaded interior along a longitudinal direction of the pistonplunger, wherein the threaded interior is threaded to correspond to thedrive screw of the drive device, and wherein the method furthercomprises operatively coupling the threaded interior with the drivescrew of the drive device when the first housing portion and the secondhousing portion are engaged.